Scavenging: Observational evidence shows that White-tailed Sea Eagles are primarily scavengers, preferring to search for animal remains that are already dead, than expend energy finding and killing their own food. Where sea eagles and Golden Eagles overlap in range, sea eagles often turn up to scavenge the remains of prey killed by Golden Eagles. Immature and adult White-tailed Eagles require on average 500-600g (1.1-1.2 lbs) of meat a day to maintain body weight although birds can survive for several days without food. Eagles consumed between 180-348g (<1lb) on average during winter at a feeding station in Finland. Thus, a small-medium sized fish or part of a rabbit carcass is sufficient for immature or adult birds to maintain daily weight. Well-grown nestlings require somewhat more for adequate development.

Live prey: Although not the species predominant foraging strategy, taking live prey is important for nesting pairs feeding young. Seabirds may be important locally where there are substantial colonies. Recent studies in Scotland suggest that of 21 pairs of nesting White-tailed Eagles most preyed on Fulmars (36% of birds in diet) rather than any other bird species (Guillemot 5%, Shag 3%, Razorbill 1.5%). In another study, birds, mainly ducks (Eider 31%) and seabirds made up most of the diet. However, birds constituted only 5% of food items brought to eagle nests in Greenland16, presumably reflecting differences in the local abundance of prey species. Waterfowl (54%), particularly Eider, were the main prey in summer in Finland along with fish (30%) with mammals (5%) relatively rare in the diet. Coots (56-58%) made up an astonishingly large proportion of the bird diet of eagles in one study in Germany.

Fish: Fish are an important part of sea eagle diet in coastal areas. Sea eagles spectacularly snatch surface-dwelling fish in flight, immersing only their talons and carrying prey to nests or nearby rocks. Saithe, Pollack, and Lumpsucker are most often taken in coastal waters in Scotland but are likely to constitute a proportion of the diet in spring and summer only before these species move to deeper waters in autumn and winter where they are unavailable to eagles. Evidence from Norway and Scotland suggest that White-tailed Eagles rarely if ever take live salmon. Even in the salmon farms, where salmon are densely crowded and easily accessible, White-tailed Eagles have rarely been seen going down to pick up fish. On the contrary, fish farmers feed eagles close to their cages to keep other problem birds away (cormorants, shags, herons, gulls). Along rivers White-tailed Eagles utilise dead and dying salmon washed ashore after spawning. In other parts of their range they hunt slow-moving, shallow water fish species, but rarely catch fast, strong fish such as salmon and trout. In some areas, White-tailed Eagles follow fishing boats where they scavenge discarded fish thrown overboard by fishermen. Such behaviour has now been exploited by fishermen in Norway and Scotland where “Sea Eagle Safaris” are an important part of the local economy (eg., www.visitbodo.com).